diff --git a/include/mbedtls/aes.h b/include/mbedtls/aes.h
index 1bfa434..4cc4d14 100644
--- a/include/mbedtls/aes.h
+++ b/include/mbedtls/aes.h
@@ -380,13 +380,18 @@
  *
  *
  * \param ctx      The AES context to use for encryption or decryption.
+ *                 It must be initialized and bound to a key.
  * \param mode     The AES operation: #MBEDTLS_AES_ENCRYPT or
  *                 #MBEDTLS_AES_DECRYPT.
  * \param length   The length of the input data.
  * \param iv_off   The offset in IV (updated after use).
+ *                 It must point to a valid \c size_t.
  * \param iv       The initialization vector (updated after use).
+ *                 It must be a readable and writeable buffer of 16 Bytes.
  * \param input    The buffer holding the input data.
+ *                 It must be readable and of size \p length.
  * \param output   The buffer holding the output data.
+ *                 It must be writeable and of size \p length.
  *
  * \return         \c 0 on success.
  */
@@ -421,12 +426,16 @@
  *
  *
  * \param ctx      The AES context to use for encryption or decryption.
+ *                 It must be initialized and bound to a key.
  * \param mode     The AES operation: #MBEDTLS_AES_ENCRYPT or
  *                 #MBEDTLS_AES_DECRYPT
  * \param length   The length of the input data.
  * \param iv       The initialization vector (updated after use).
+ *                 It must be a readable and writeable buffer of 16 Bytes.
  * \param input    The buffer holding the input data.
+ *                 It must be readable and of size \p length.
  * \param output   The buffer holding the output data.
+ *                 It must be writeable and of size \p length.
  *
  * \return         \c 0 on success.
  */